Evidence suggesting that a transcortical reflex pathway contributes to cutaneous reflexes in the tibialis anterior muscle during walking in man

摘要: Stimulation of cutaneous foot afferents has been shown to evoke a facilitation the tibialis anterior (TA) EMG-activity at latency 70–95 ms in early and middle swing phase human walking. The present study investigated underlying mechanism for this facilitation. In those subjects whom it was possible elicit reflex during tonic dorsiflexion while seated (6 out 17 tested), TA EMG evoked by stimulation sural nerve (3 shocks, 3-ms interval, 2.0–2.5× perception threshold) found have same observed suggested be – least partly mediated transcortical pathway. To investigate whether similar contributes walking, magnetic motor cortex (1.2× applied different intervals relation subjects. 13 subjects, potentials (MEPs) were more facilitated prior sural-nerve (conditioning-test 50–80 ms) than algebraic sum control MEP when separately. four these H-reflex could also none an increase that observed. five experiments on MEPs electrical cortical compared. experiments, only magnetically induced nerve. We suggest pathway may contribute late reflexes